/*---------------------------------------------------
int i2c_gpio_phase_start();
Generate i2c_gpio_phase_start Condition:
Stream Format:
SCL _____/--------\___
SDA =---------\_____
width (4.7u)4.7u|4.7u|
Arguments:
NONE
Return value:
int SUCCESS 0
int ERR_STATUS 1
----------------------------------------------------*/
static RET_CODE i2c_gpio_phase_start(i2c_gpio_priv_t *p_priv)
{
/* Make sure is out */
SET_SDA_OUT(p_priv);
SET_SCL_OUT(p_priv);
SET_SDA_HI(p_priv); /* Set SDA high */
if(0 == GET_SCL(p_priv))
{
I2C_GPIO_DELAY_US(p_priv->clock_period);
}
SET_SCL_HI(p_priv); /* Set SCL high */
I2C_GPIO_DELAY_US(p_priv->clock_period);
if(0 == GET_SCL(p_priv))
{
return ERR_STATUS;
}
if(0 == GET_SDA(p_priv))
{
return ERR_STATUS;
}
SET_SDA_LO(p_priv);
I2C_GPIO_DELAY_US(p_priv->clock_period);
SET_SCL_LO(p_priv);
return SUCCESS;
}
//------------------------------------------------------------------------------
// Function: SetSCLHigh
// Description:
//------------------------------------------------------------------------------
static uint8_t SetSCLHigh(void)
{
volatile uint8_t x = 0; //delay variable
uint32_t timeout = 0;
// set SCL high, and wait for it to go high in case slave is clock stretching
SET_SCL();
x++;
x++;
x++;
x++;
while (!GET_SCL())
{
/* do nothing - just wait */
//udelay(2);
timeout++;
if( timeout > 100000 ) // about 1s is enough
{
printk("\n ************IIC SCL low timeout...\n");
return IIC_SCL_TIMEOUT;
}
}
return IIC_OK;
}
static uint8_t i2c_soft_receive_bit(void)
{
// SDA = 1
// SCL = 1
// wait SCL low
// bit = SDA
// SCL = 0
uint8_t bit;
SDA(1);
waitSomeTimeInUs(1);
SCL1();
waitSomeTimeInUs(1);
while( GET_SCL() == 0);
bit = GET_SDA();
SCL0();
SDA_OUTPUT();
waitSomeTimeInUs(1);
return bit;
}